Many mineral resources and metals are vital to our Nation’s economy and national security. They are necessary manufacturing components for military hardware throughout the defense industrial base, including fighter jets and submarines, as well as for the technology and electronics we use every day, such as mobile batteries for power tools, smartphones, and vehicles.

Since Executive Order 13817 in 2017, the USGS has analyzed supply chains for these materials to develop the whole of government List of Critical Minerals. The list, due to be revised in June 2025, currently includes 50 minerals whose supply must be assured to avoid significant consequences to the United States economy and national security. 

Across the USGS, research is underway to better understand the life cycle and supply chains of mineral resources, with a focus on those critical minerals. The Coastal and Marine Hazards and Resources Program maps the seafloor and provides the science necessary to characterize potential resources offshore. 

Like minerals on land, deep sea minerals occur in a wide variety of settings related to Earth’s geologic framework and history. We investigate how and where they form, what conditions contribute to their growth, how long it takes for them to accumulate, identify where other similar minerals might occur, and assess the potential environmental signals associated with their extraction. 

Our research focuses on the marine mineral categories that have the greatest resource potential, including manganese nodules, ferromanganese crusts, seafloor massive sulfides, and marine phosphorites. 

Manganese nodules are spheroidal rocks that also form over millions of years, atop sediment covering the abyssal plains of the ocean. They are of great interest for mining due to high concentrations of manganese, nickel, copper, and sometimes lithium.  

Ferromanganese crusts are seafloor pavements and encrusted rocks on the seafloor that grow very slowly, at several millimeters per million years, onto exposed rock surfaces throughout the ocean. They absorb metals and other elements from seawater over long periods of time and are especially enriched in cobalt, manganese, rare metals such as tellurium, precious metals such as platinum, and rare earth elements.  

Seafloor massive sulfides, also known as polymetallic sulfides, form at hydrothermal vents from reduced sulfur. They may be enriched in copper, zinc, iron, gold, and silver. 

Marine phosphorites form along continental margins where upwelling of cold, nutrient-rich, deep water is strong (i.e., Peru-Chile margin, Chatham Rise offshore New Zealand, and the Blake-Bahamas Plateau off the southeast United States) and on seamounts where ferromanganese crusts grow. They are sources of phosphate used as fertilizer for agriculture and phosphoric acid in the food industry. They also contain high concentrations of valuable, heavy, rare-earth elements. 

Our scientists analyze mineral samples to understand their composition and metal content, examining how these factors vary across different regions. This helps identify promising areas in the ocean where mineral resources may exist by examining the relationship between ocean conditions and geographical features. We also investigate mineral stability and metal mobility by assessing how they react to seawater over time to learn how geochemical effects could disturb these resources. 

We report our findings to U.S. leaders, industry, and the public so they can better understand the mineral wealth within the offshore territory of the United States and make decisions about which regions and resources warrant further research. We make the maps, our leaders decide on resource management, and private industry conducts exploration and proposes next steps.  

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Visit the Global Seabed Mineral Resources project web page to learn more.